How get tags for EC2 or EBS, when call Amazon CloudWatch ListMetrics action time

i am creating CloudWatchService. ListMetrics action calling time, i am getting result json:

{Namespace: AWS/EC2,MetricName: DiskWriteBytes,Dimensions: [{Name: InstanceId,Value: i-XXXXXXXX}]}

I need than my result getting ec2, ebs tags also.

have an idea how to implement it, except for the call of a new request and after that configuring response json. (ec2 or ebs)?

thanks